A universal influenza vaccine by dual-domain fusion with a novel carrier protein

描述(申请人提供)：流感病毒的快速基因变化继续给目前针对特定毒株的流感疫苗提供足够的流感流行控制和有效的大流行对策带来巨大困难。因此，迫切需要一种针对保守的抗原域并提供对所有流感病毒株的保护的通用疫苗。M2e和融合肽(FP)是在流感病毒表面蛋白中发现的两个高度保守的抗原域。M2e(24个氨基酸)在所有A型流感病毒中都是保守的，FP(14个氨基酸)在A型和B型流感病毒中都是保守的。目前通用疫苗的开发工作主要集中在基于M2e的单域结构上。由于保守的抗原域仅由短肽组成，有效的多价蛋白载体系统在生产、储存、分配和使用方面对于提高疫苗的有效性和产品的可行性至关重要。 KJ生物科学公司旨在通过开发一种新型双域通用流感疫苗来满足这一迫切需求，该疫苗同时包含M2e和FP抗原域，将提供对所有甲型和乙型流感病毒的保护，因此可用于控制流感流行和大流行。它将通过与一种独特的纳米蛋白质载体进行双域融合而产生，该载体的N-末端和C-末端都暴露在表面以用于抗原附着。根据载体蛋白的独特性质，疫苗产品也可以在室温或更高温度下稳定下来。耐热疫苗将显著减少疫苗产品的储存、分发和使用的后勤需求，这在面对大流行时尤为重要。 这项提议的目标是在初步研究的有希望的结果的基础上继续开发这种双域通用流感疫苗。拟议的研究有两个具体目标。 具体目标1：融合蛋白的产生和鉴定。利用重组DNA技术，将M2e和FP抗原结构域排列在不同位置的双域融合蛋白与纳米载体蛋白构建成融合蛋白。他们将接受测试，以展示纳米颗粒的形成，与抗原域的特异性抗体的反应，以及在室温或更高温度下的稳定性。 具体目标2：免疫原性和保护性。选定的双域融合蛋白候选疫苗(S)将在动物模型中进行测试，以证明该候选疫苗能够诱导特异性抗体，并保护动物免受活流感病毒的攻击。 这两个特定目标的完成将为进一步的临床前免疫原性评估和工艺开发奠定基础，以生产毒理学和I期临床研究的候选疫苗。这种疫苗的成功开发将为控制流感疫情提供有效措施，并大大提高我们应对未来大流行的能力。 与公共卫生的相关性：流感病毒的快速变化继续给当前针对特定毒株的流感疫苗在充分控制流感流行和有效应对大流行方面造成极大困难。该项目旨在开发一种新的双域通用流感疫苗，该疫苗可用于控制季节性流行病和大流行，也可在不冷藏的情况下快速生产和分发。这种疫苗是通过使用来自细菌的独特载体蛋白将两个高度保守的流感抗原域结合在一起而成为可能的。

DESCRIPTION (provided by applicant): The rapid genetic changes of influenza viruses continue to cause great difficulties with current strain- specific influenza vaccines in providing adequate control for influenza epidemics and effective countermeasures against pandemics. Thus, a universal vaccine that targets conserved antigen domains and provides protection against all influenza virus strains is urgently needed. The M2e and fusion peptide (FP) are the two most highly conserved antigen domains found in influenza virus surface proteins. The M2e (24 amino acids) is conserved among all influenza A viruses and the FP (14 amino acids) is conserved among both influenza A and B viruses. Current development efforts for a universal vaccine have primarily focused on single-domain constructs based on M2e. As the conserved antigen domains consist of just short peptides, an effective multivalent protein carrier system is critical in enhancing vaccine effectiveness and product feasibility with respect to manufacturing, storage, distribution, and use. KJ Biosciences aims to meet this urgent need by developing a novel dual-domain universal influenza vaccine incorporating both M2e and FP antigen domains that will provide protection against all influenza A and B viruses and can therefore be used to control influenza epidemics as well as pandemics. It will be produced by dual-domain fusion with a unique nanoparticle protein carrier that has both N- and C-termini exposed on the surface for antigen attachment. The vaccine product can also be stabilized at room or higher temperatures based on the unique properties of the carrier protein. A thermostable vaccine will significantly reduce the logistical requirements for storage, distribution, and use of the vaccine product, which is especially important when facing a pandemic. The goal of this proposal is to continue to develop this dual-domain universal influenza vaccine based on the promising results from preliminary studies. The proposed studies have two specific aims. Specific aim 1: Generation and characterization of the fusion proteins. Dual-domain fusion proteins with M2e and FP antigen domains arranged in different positions will be generated with the nanoparticle carrier protein by recombinant DNA techniques. They will be tested to demonstrate nanoparticle formation, reaction with antibodies specific to the antigen domains, and stability at room or higher temperatures. Specific aim 2: Immunogenicity and protection. Selected dual-domain fusion protein vaccine candidate (s) will be tested in animal models to demonstrate that the vaccine candidate can induce specific antibodies and protect animals against challenge with live influenza viruses. Completion of these two specific aims will form the basis for further preclinical immunogenicity evaluation and process development to produce the candidate vaccine for toxicology and phase I clinical studies. Successful development of this vaccine will afford an effective measure for controlling influenza epidemics and also greatly enhance our ability to respond to future pandemics. PUBLIC HEALTH RELEVANCE: The rapid changes of influenza viruses continue to cause great difficulties with current strain-specific influenza vaccines in providing adequate control for influenza epidemics and effective countermeasures against pandemics. This project aims to develop a novel dual-domain universal influenza vaccine that can be used to control seasonal epidemics as well as pandemics and also be rapidly produced and distributed without refrigeration. This vaccine is made possible by incorporation of two highly conserved influenza antigen domains using a unique carrier protein from bacteria.